Stock compensation expense (Details) - USD ($)	3 Months Ended	6 Months Ended
	Oct. 31, 2021	Oct. 31, 2021
Share-based Payment Arrangement [Abstract]
General and administrative	$ 389,749	$ 609,350
Research and development	84,752	141,232
Operations	311,347	374,608
Sales and marketing	114,089	158,833
Total	$ 899,937	$ 1,284,023